Overhead closure safety halting system and actuator therefor



Sept. 19, 1961 G. P. GESSELL 3,001,038

OVERHEAD CLOSURE SAFETY HALTING SYSTEM AND ACTUATOR THEREFOR Filed April 14, 1958 2 Sheets-Sheet 1 RQ- 5 H INVEN TOR /24 //Z G/QWP Gene 4 //a Q b mMfau ga, j/Hyg 3,001,038 OVERHEAD CLOSURE SAFETY HALTING SYSTEM AND ACTUATOR THEREFOR Filed April 14, 1958 Sept. 19, 1961 G. P. GESSELL 2 Sheets-Sheet 2 w f g aw, \Wd W \7P. R W J, E W

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United States Patent 3,001,038 OVERHEAD CLOSURE SAFETY HALTING SYSTEM AND ACTUATOR THEREFOR Glenn P. Gessell, 930 Lake Shore Road, Grosse Pointe Shores, Mich. Filed Apr. 14, 1958, Ser. No. 729,048 3 Claims. (Cl. 200-61.43)

This invention relates to closure safety devices and, in particular, to devices for controlling motorized closures, such as overhead doors. 1

One object of this invention is to provide an obstructionresponsive motorized closure controlling system and actuator therefor which will automatically break the energization circuit of a motorized closure operating motor in response to the encountering of an obstruction, whereby .the movement of the closure is automatically halted or reversed before the closure can inflict any damage to the closure, its operating mechanism or the obstruction.

Another object is to provide an obstruction-responsive motorized closure controlling system of the foregoing character wherein the closure is halted quickly and effectively, regardless of the location within the closure opening at which the obstruction is encountered.

Another object is to provide an obstruction-responsive motorized closure controlling system of the foregoing character which is operated by mechanically and electrically-acting components without the need for delicate and expensive electronic and/or photoelectric components which not only have a high first cost of purchase and installation but also involve high maintenance cost.

Another object is to provide an auxiliary safety obstruction-responsive motorized closure controlling system of the foregoing character wherein the auxiliary safety system is normally inoperative during operation of the main closure-operating circuit in normal and unobstructed movement of, the closure, even during entirely unobstructed movement but becomes instantly operative when a contact member of the actuator collides with the obstruction, .so that the closure operates ordinarily independently of and without affecting the auxiliary safety closure controlling system, and is halted at the open and closed positions of its path oftravel by the normal limit switches or other means regularly associated with the main closure-operating circuit of a conventional closure operator for so halting the closure.

Another object is .to provide an auxiliary safety ob struetion-responsive motorized closure controlling system wherein the auxiliary safety closure controlling circuit of theactuator is never energized except during the period when current is being supplied to the main closureoperating motor energization circuit.

Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawings, wherein:

FIGURE 1 is a rear elevation of an overhead closure equipped with an actuator for an obstruction-responsive motorized olosure controlling system, according to one form of the invention, shortly before the closure has reached the lower limit of its descent;

FIGURE 2 is a view similar toFlGURE l, butshowing the relative positions of the parts after the closure has reached the bottom of its normal path of descent, and engages-the floor; a

' FIGURE 3 isan enlarged rear elevation of one of the movable actuator supports with a portion of the contact member shown at the left-hand corner of FIGURE 2;

FIGURE 4 is a section taken along the line 44 in FIGURE 3, with a portion of the movable support broken away to disclose the insulating arrangement for its electrical contacts; and

FIGURE 5 shows one type of wiring diagram usable Patented Sept. 19, 1961 with the closure safety controlling system, including the actuator, according to the present'invention.

Hitherto, the halting of overhead closures, such as overhead garage or warehouse doors or the like, has been a serious problem where an obstruction is suddenly interposed beneath the door. The weight of a large door is so great that its inertia tends to cause injury to persons or damage to property obstructing its path of descent before any electric operating motor can stop, halt the door and reverse its path of travel. This is particularly true in the case of prior mechanical contact appliances installed at the lower edge of the door, the inertia of the door and time lag of the operating or halting system causing such injury to persons or damage to property. A common example of such an obstruction is a vehicle passing through the door opening'at the time the door has started its descent, particularly if the person controlling the door was unaware that the vehicle had entered the door opening after he had initiated the door closing operation.

' Prior photo-electric control systems for the door operator have partially solved the problem because they can be set in motion to halt the door before it has arrived at the obstruction, thereby allowing for the inertia and momentum ofthe door as well as the time lag of prior safety devices. Such photo-electric control systems are expensive both in installation and maintenance and are beyond the reach of the majority of owners of such door installations. A prior safety halting system having a contact member consisting of a Wire stretched across the bottom of the door 'is simple buton-ly partially effective, particularly at the side of the door nearest the switch operated by it, and is very inefficient near the center of the door where an obstruction can deflect the wire considerably before the safety halting device becomes opera tive, because of the extremely large angle which the two portions of the wire on opposite sides of the obstruction make with one another.

The present invention provides an obstruction-responsive overhead closure halting system of 'low cost installation and maintenance and of great dependability, as well as one which is operative quickly and effectively without damageto the obstruction or injury to a person inadvertently being beneath the door during its descent, yet which is operative efiiciently regardless of Whether the obstruction is encountered near the center of the door or near one side thereof. Moreover, the safety halting obstruction-contacting member is so mounted on the door as not to interfere with the regular halting of the door at its opposite limits of descent and ascent and becomes operative only upon encountering an obstruction at a point between those limits. Finally, the actuator for the obstruction-responsive overhead closure halting system of the present invention is energized only when current is being supplied to the motor of the door operator and not otherwise. The present system is applicable either to installation upon existing doors or to being built into doors of future manufacture at the factory. I

Referring to the drawings'in detail, FIGURE 1 shows an overhead closure installation, generally designated 10, of conventional design equipped with an obstructionresponsive overhead closure halting system, generally designated 12, controlled by an actuator, generally designated 14, forming the mechanical part of the system 12 and attached to the lower section 16 near the lower edge 18 of an overhead door 20. The overhead door 20 is conventional and its details are beyond the scope of the present invention. In the example shown, the lower section 16 is connected to the section 22 above it by hinges 24, the outermost hinges 24 or cable attachment plates 26 bolted to the lower corners of the lower door section 16 carrying rollers 28 travelling in upwardly-dii other flexible force-transmitting members 40which extend upward to a conventional"spring-loaded counterbalancing mechanism (not shown) The overhead door 28 is raised or lowered within the door opening 36' by any suitable conventional door operator (not shown).

The actuator '14 is mounted on U-shaped brackets or support-guiding attachmentmembers 46 (FIGURES 3 and 4) which are bolted or otherwise secured to the lower section 16 near its opposite side edges 44. The U-shaped brackets 46 carry sliding circuit-closing supports 48 fora safety obstruction-engaging bar or contact member 50 which is also slidably mounted on its supports 48. If the door 20* is of extreme Width for an excessively wide opening 36, other intermediate supports 43 are secured to the door section 16 at intermediate locations, such as, for example, in the center of the lower door section '16 or at otherpoints necessary to give proper support and comparative freedom of sagging to the safety bar 50'. The U-shaped brackets 46 are pro V vided with upper and lower aligned holes 52 (FIGURE 4) through which the supports 48 looselyand slidably pass and are limited in their downward motion by'c ollars 54 secured near their upper endsf by set screws 56.

The supports 48 are of tubular or pipe form with their upper and lower ends of their bores 58 closed by plugs 60 and 62, the upper plugs 60 being provided with a central hole 64 for the passage of a two-conductor electric cable 66, and the lower plugs 62 having lower groundengaging surfaces 67. The cable 66 emerges through a hole 68 in each support 48 fromthe bore 58 thereof and its individual conductors 70 and 72 are connected .to contact elements 74 and 76 secured by terminal screws 'as the outside hinges 24, their rollers 28 and the guide rails 38.

The horizontal safety bar 50is also'in the form of a tube or pipe (FIGURE 4) having upper and lower "and slidably receiving the lower end portions of the tubular supports 48. The safety bar 50 is limited in its descent by interrupted rectangular bails 90 having their spaced lower ends 92 insertedthrough aligned holes 94 in the opposite sides of the supports 48 a short distance above the lower ends of the lower end plugs 62. The

bails 9 0 are of suflicient lengthso as to normally lie in inclined positions (FIGURE 3) but to swing upward if the safety bar 50 encounters an obstruction and is pushed upward along the tubular supports 48. The safety bar 50 at its opposite ends carries contact washers 96 which ride upon the upper side of the bar50 immediately above the upper holes 86 and immediately beneath the contact elements 74 and 76.

v The obstruction-responsive system 12, in addition to'the overhead closure halting actuator 14 (FIGURE 5) includes a latching relay, generally designated 100, a reversible electric motor 102 connected to the door operator mechanism, a normally 184, and a stepdown transformer 106 for furnishing control current at a lower voltage'than the motor energization current received from powercurrentlines108 and 110 connected to an external source of electric power current (not shown).

The stepdown transformer I106 116 leading to the power currentsupply lines 108 and aligned holes 86 and 88 respectively (FIGURE 3) loosely 1 overhead closure halting a openpush button motor starting and stopping switch I has a primary winding t 1 .1 12 which is continuously energized by the lines 114 and transformer 106"has theusual iron core 118 and a' secondary stepdown winding 120, one end of which is grounded as at '122 by the line 124'to the same conducting structure as the ground of the line 70.

From the oppositeend of the transformer secondary winding 120, the line 126 runs to one end of the operating coil 128 of the latching relay'100. From the opposite end of the operating coil 128, the line 130 runs to one pole of the normallyopen motor starting and stopping push button switch 104 from the opposite pole of which the line 132 runs to a ground connection 134 on the same metallic conducting structure as the previouslymentioned ground'connections 85 and 122. The operating coil 128 of the latching relay 100 operates an armature 136 having a contact-operating'link 138 for altering iixed gar-ms144 and 146 betweenfy/hich is a movable upper intermediate arm .148. Theilpper and lower fixed 7 arms 144 and 146 are provided with single contacts 158 and 152 respectively engageab-l'e with oppositelyqfa'cing movable contacts 154 and 156 on the upper and lower sides of the movable arm 148 and alternately engageable with the fixed contacts-.150 and 152. In a similar manner, the lower contact, set 142 includes fixed upper and lower contact arms158- and 160 between which is a movable intermediate contact arm 162. The fixed lower contact arms 158 and .160 of the lower contact set 142 are provided with single contacts 164 and 166 alternately engaged by oppositely-facing contacts .168 and 170 on the movable intermediate contact 162. Them-mature link 138 is connected to the upper and lower intermediate contact arms .148 and 162, and in the deenergized con- 'dition of the latching relay 109, the upper contacts 154 and 168 of the upper and lower intermediate arms 148 and 1 62 are normally engaged with and closed upon the upper fixed contacts and 164 respectively. These contacts are opened in response to the energization of the operating coil 128 to close the circuit between the intermediate arms 148 and 162 and the contacts 152 and 166 of the lower arms 146 and 160, as explained below in connection with the operation of the invention.

The latching relay, as its name suggests. is of a wellknown type having a mechanical latching arrangement (not shown) operated by alternate successive energizetions of the operating coil .128 and by consequent alternatesuccessive shiftings of the armature 136 and armature'link 138. The current supply line 108 is connected directly to the lower contact arm .160 of the lower contact set 142, whereas the line 169 runs from the movable contact arm 162 to the motor 102, the opposite pole or terminal of which is connected directly to the power current supply line 110. From the line 130 a branch line 171 runs to the lower fixed contact arm 146 of the upper Bergernann Patent No. 2,531,838 of November 28, 1950 a for Latching Relay and such latching relays of this pat-.

ented construction'are available on the open market. In

such a relay, alternate successive energizations of the e operating coil 128 first hold the lower contacts 156 and 170 of the movable intermediate arms 148 and 162 in engagement respectively with the contacts 152 and. 166

of the lower'fixed contact arms-146 and of the upper and lower contact sets 140' and .142, and next release the latching device (not shown) to release thesecontacts to return totheir normally-de-energized positions shown in FIGURE 5. In other words, the first energization,

brought about by depressingthepush-button switch;104,. f

engages the contacts 156-152 and -166;the next energization, either by the pushbutton switch 104 onby the closing of the contacts 74-76 of the actuator 14 by thebar-operated contact washer or washers 96, releases" the latching device to. disengage these contacts; the-third energi'zationrre-engages. them; the fourth energization again disengages them, and so 'forth indefinitely. The latchingv device of the latching relay 100 is primarily mechanical rather than electrical, although operatedb'y the successive shiftings of the armature 136,. as disclosed in the above-identified Bergemann Patent 2,531,838. In the operation of the invention, letit be assumed that the door 20 is in its raised-position and that as a consequence; the'sliding circuit-closingsupports 48, together with the safety obstruction-engaging bar 50, are hanging from the door 20 their lowered positions with therbar 5,0-resting against the lower ends 'of the bails 90 in the positions shown in FIGURE 1., To causethe door 20 to descend, the operator closes the push buttoniswitch 104 (FIGURE 5), thereby completing the energization circuit of the operating coil 128 of the latching relay 100 from the secondary winding 120 of the transformer 106, the primary 112 of which is continuously energized by -the lines1i114 and 116 from the power current supply lines 108 and 110 as long as these are alsoenergized. The energization of the operating coil '128 takes; place m h hc .linesplzfi and .9 c ne e to ecppo t ports 48, moving relatively thereto until either or both the contact discs 96 bridges the contacts 74 and 76. When this occurs, the consequent closing'of the circuit between the lines 70 and 72 (FIGURE 5) re-energizes the operating coil 128 of the latching relay 100 by way of the ground connection 122, the line 124, the transformer secondary winding 1-20,the line 126, the coil 128, the line 130, the line 171, the lower fixed contact arm 146 and contact 152 of the upper contact set 140, the lower movable contact 156 and movable arm 148 thereof, the line 72, the contact 76, the contact washer 96, the contact 74, the line 70 and the ground connection 85, completing the circuit.

The re-energ'ization or second energization of the operating coil 128 releases its mechanically-operated latching mechanism described in the above-identified Bergemann Patent 2,531,838, thereby releasing the movable relay fcontact arms 148 and 162 to spring upward to their raised positionsshown in FIGURE 5. This action consequently de-energi zes the energization circuit of the motor 102 and haltstlrelmotor 102 ,by:interrupting the connection at the now-separated contacts 166 and 170 between the current supplyline108 and the motor-energiza-tion line 1 69.

ends of the operating coil 128, the transformer secondary winding 120, the line .124, the ground connections 122.

and 134, the line 132 and the now closed push .button switch 104, completing the circuit.

The first energization, in this manner, of the operating coil 128 of the latching relay 100 shifts the armature 136 and armature link 138 and with them the movable contact arms 148 and 162 of the upper and lower contact sets 140 and 142. This action engages their contacts 156 and 170 with the fixed contacts 152 and 166 of the fixed lower arms 146 and 160 respectively, while at the same time the mechanically-operated latching mechanism shown and described in the above-identified Bergemann Patent 2,531,838 holds these contacts in engagement with one another even though the operator immediately releases the push button switch 104 and thereby de-energizes the latching relay operating coil 128.

As a result of this action, the door-operating motor 102 is energized from the current supply line 110 through the motor winding, the line 169, the lower movable contact arm 162, the now closed contacts 170 and 166, the lower fixed contact arm 160 of the contact set 142, and the current supply line 108 connected directly theretocompleting the circuit. Consequently, the motor 102 starts running and causes the door or other closure 20 to descend from its raised position with the lower ends of the supports 48 and the safety obstruction-engaging bar 50 projecting below the lower edge 18 of the closure 20.

If no obstruction presents itself below the descending door or other closure 20, the door 20 descends normally and the motor 102 is halted normally by a conventional limit switch (not shown) included in the motor-energization circuit. As the door 20 reaches its lowermost position and its lower edge approaches the level of the floor F, the lower end surfaces 67 ofthe supports 48 engage the floor F and push the supports 48 upward in their brackets 46, the bar 50 remaining in its lower position against the lower portions of the bails 90 (FIGURES 2, 3 and 4) without rising to close the circuit between the contacts 74 and 76. As a result, the overhead closure halting systom 12 remains inoperative, and the door or other closure 20 is brought to a halt by its regular limit switch (not shown) and associated circuits.

If, instead, during the descent of the door or other closure 20, an obstruction, such as a motor vehicle, presents itself below the descending door 20, the safety 0bstruction encountering bar 50 collides with the obstruction before the lower edge 18 of the door 20 reaches the obstruction and is pushed upward along the slidable sup- As-, a, r esult, due to the fact that the safety obstruction engaging" bar; 50 projects below the lower edge 18 of the door '20, the bar 50 can continue to move upward, pushing the supports 48 upward in their brackets 46 while the door 20 is coming to a halt. Thus, notwithstanding the heavy weight and consequent inertia and momentum of the descending door or other closure 20, the latter will come to a halt before its lower edge 18 encounters and damages itself or the obstruction, or injures the person if the obstruction is a person, due to the fact that the upward motion of the bar 50 and its supports '48 gives adequate time for the motor 102 and door 20 to halt safely above the obstruction.

Since the bar 50 is a relatively rigid object, contact of it with the obstruction at any point between its opposite ends will cause it to move upward to bridge at least one set of the contacts 74 and 76, thereby actuating the motorhalting system 12 in the manner described above. On the other hand, normal operation of the door 20 is in no wise interfered with, because the lower end surfaces 6-7 then engage the floor F and push the supports 48 and bar 50 upward without bridging the contacts 74 and 76. Furthermore, the actuator 14 including the supports 48 and bar 50 and the system 12 of which it is a part are never energized except during the period when electric current is being supplied to the energization circuit of the closure operating motor 102.

While the invention has been described in connection with an installation on a vertically-movable overhead door, it will be evident that it is also capable of installation on the vertical edge of a horizontally-movable door, with the same advantages. In such an installation, it is of course necessary to add springs to urge the sliding circuit-closing supports 48 outward and also weaker springs to similarly urge the safety contact bar 50 outward, assuming the supports 48 to be now horizontal and the bar 50 to be vertical, rather than in the positions shown in FIGURES 3 and 4. These springs are unnecessary in the installation on a vertically-movable door because, of course, the force of the gravity acting upon the weight of the supports 48 and bar 50 urges these members downward into their normally inactive or extended positions. In other Words, the springs are added to an installation on the vertical edge of a horizontallymovable door in order to provide the force otherwise applied by gravity and the weight of the elements concerned.

It will also be evident that the invention may be used, not merely to halt the door-operating motor 102 and consequently halt the door 20 in its attained position when the obstacle is encountered by the bar 50, but alterna: tively to reverse the motor 102 and thereby cause the 7 7 door-20 to move to its open position afterthe' safety contact bar 50 encounters the obstaclc. I a

It .will finally be evidentthat instead of the motor 102 {FIGURE 5 there may be substituted a solenoid which when energized and de-energized respectively controls the actuation of a valve which in turn controls the operation of a fluid pressure motor (such as a hydraulic or compressed air motor') to move the door between its open and closed positions.- v What I claim is: i t

1. An obstruction-responsive actuator for a safety closure travel interrupting system of an electric-motor-operated overhead closure, comprising a plurality of support-guidi'n-g attachment members adapted tobe secured to the closure near the leading edge thereof in laterallya spaced relationship, a forwardly-urged support guidedly and slidably mounted in each attachment member and having electric switch means thereon, and an elongated safety-obstraction-engaging member adapted to be disposed substantially parallel to=the leading edge of the closure and slidably mounted on said supports for travel mal building structure during normal operation of the closure.

2. An obstruction-responsive actuator, according to claim 1 wherein the switch meansincludes a pair of spaced contacts and wherein the obstruction-engaging member carries-a contact-actuating pontion adapted to close the circuit between said contacts inresponse to the shifting of said member. or

' 3. An obstruction-responsive actuator, according to claim 1, wherein said supports also carry rearward travellirniting elements restraining the range of travel of said obstruction-engaging member to a predetermined from an' advanced position disposed at a predetermined distance rearwardly from the. forward ends of said supports to a retractedpo sition 'operatively engaging said switch means, said supports having forwardstop elerange rearwardly from said forward stop elements. 7 References Cited in the file of this patent p UNITED STATES PATENTS f Greegor et al. Nov. 12, 1-940 2,401,082. Konter May 28, 1946 2,7033235 Reamey a Mar; 1, 1955 2,789,636

Lawick .e Apr; 23, 1957 

